This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A063848 #17 Jun 25 2018 03:42:26
%S A063848 14,20,32,34,38,55,56,84,86,91,92,94,117,118,121,122,132,133,140,142,
%T A063848 143,144,145,158,159,176,183,200,202,203,204,205,208,212,214,215,216,
%U A063848 218,219,235,247,252,297,298,299,300,302,303,319,325,326,327,328,333
%N A063848 Numbers k such that mu(k) + mu(k+1) + mu(k+2) = 2.
%H A063848 Harry J. Smith, <a href="/A063848/b063848.txt">Table of n, a(n) for n = 1..1000</a>
%t A063848 Flatten[Position[Partition[MoebiusMu[Range[350]],3,1],_?(Total[#]==2&),{1},Heads->False]] (* _Harvey P. Dale_, Nov 26 2015 *)
%o A063848 (PARI) m(n) = moebius(n)+moebius(n+1)+moebius(n+2);
%o A063848 j=[]; for(n=1,1000, if(m(n)==2,j=concat(j,n))); j
%o A063848 (PARI) M(n) = moebius(n) + moebius(n + 1) + moebius(n + 2)
%o A063848 { n=0; for (m=1, 10^9, if(M(m)==2, write("b063848.txt", n++, " ", m); if (n==1000, break)) ) } \\ _Harry J. Smith_, Sep 01 2009
%Y A063848 Cf. A063838.
%K A063848 easy,nonn
%O A063848 1,1
%A A063848 _Jason Earls_, Aug 26 2001